Surge protection devices (SPDs) are typically designed to monitor input electrical power and to rapidly remove such power, such as by automatic operation of a switch device, from internal and externally connected load circuits in response to overvoltage and/or undervoltage conditions, wiring faults, etc. Depending on the implementation, the response time with which SPDs can interrupt delivery of electrical power is typically very fast, e.g., about 20 ms measured from the onset of a power event, such as an overvoltage event.
Certain conventional SPDs provide mechanisms that allow a user to set thresholds by which overvoltage/undervoltage events are defined, but do not allow the user to control the aggressiveness with which such undervoltage/overvoltage power events precipitate a device shutdown. Accordingly, low energy switching voltage transients, such as those that occur during power cycling of specific types of connected equipment (cooling fans, for example), can cross a user-defined voltage threshold and cause unintended power interruptions.